CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Dead cell causes singularity?

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 28, 2011, 13:44
Default Dead cell causes singularity?
  #1
liu
Senior Member
 
Xiaofeng Liu
Join Date: Mar 2009
Location: State College, PA, USA
Posts: 118
Rep Power: 17
liu is on a distinguished road
I have a mesh where there is a cell which is totally surrounded by walls, i.e., it is a "dead" cell. This cell is isolated from others.

When I do icoFoam, it exited with a segment fault.

So what could be the problem? Does this cause singularity? Or the status of the system is undetermined?

One thing I might do is to delete these "dead" cells from the mesh since they don't contribute to anything. But how can I do that?

Thanks.
Attached Images
File Type: jpg dead_cell.JPG (26.2 KB, 19 views)
liu is offline   Reply With Quote

Old   October 1, 2011, 16:38
Default
  #2
Retired Super Moderator
 
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
Posts: 10,981
Blog Entries: 45
Rep Power: 128
wyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to all
Greetings Xiaofeng Liu,

Check this tutorial: http://openfoamwiki.net/index.php/SetSet
You can use those instructions as a reference to the steps you need to do:
  • Run checkMesh to create the cellSets for the list of damaged cells;
  • Then use setSet to select said cellSets, then invert selection to select the good part of the mesh;
  • Then use subsetMesh for saving only the good part of the mesh.
Good luck!
Bruno
__________________

Last edited by wyldckat; October 14, 2011 at 18:21.
wyldckat is offline   Reply With Quote

Old   October 14, 2011, 11:28
Default
  #3
liu
Senior Member
 
Xiaofeng Liu
Join Date: Mar 2009
Location: State College, PA, USA
Posts: 118
Rep Power: 17
liu is on a distinguished road
Thanks for the reply, though you answer is not relevant.

I have figured out this. For the record, it seems that those dead cells has no effect on the solution at all. They are not participating in the calculation since no flux could pass through the surrounding walls.

You might be able to subSet these cells out but again it is not necessary.
liu is offline   Reply With Quote

Old   October 14, 2011, 18:23
Default
  #4
Retired Super Moderator
 
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
Posts: 10,981
Blog Entries: 45
Rep Power: 128
wyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to allwyldckat is a name known to all
Hi Liu,

Well, I can't always be right But still, I did (sort-of) answer your last question on the initial post:
Quote:
Originally Posted by liu View Post
One thing I might do is to delete these "dead" cells from the mesh since they don't contribute to anything. But how can I do that?
But I'm glad you figured it out by yourself

Best regards,
Bruno
__________________
wyldckat is offline   Reply With Quote

Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cells with t below lower limit Purushothama Siemens 2 May 31, 2010 22:58
IcoFoam parallel woes msrinath80 OpenFOAM Running, Solving & CFD 9 July 22, 2007 03:58
Could anybody help me see this error and give help liugx212 OpenFOAM Running, Solving & CFD 3 January 4, 2006 19:07
[Commercial meshers] Trimmed cell and embedded refinement mesh conversion issues michele OpenFOAM Meshing & Mesh Conversion 2 July 15, 2005 05:15
Warning 097- AB Siemens 6 November 15, 2004 05:41


All times are GMT -4. The time now is 06:10.